Theres plenty of information here. If youre looking to learn about what people are telling you to put in your pc though id suggest looking at a couple of sites. i reccommend extremetech.com. They do alot of bang for your buck builds that can start out as a guide. I prefere my pcs to not make any noise, so heres what i would recommend.
antec p180
nexus fans
amd 64 3200+ or 3500+ (make sure to get 939)
Id replace the stock HSF with a Scythe ninja, also with a nexus fan.
a 939 motherboard (stay with 939 in case you want to upgrade later, and also stick with reliable brands -- asus & msi. ) look for on board gigabit lan too.
for a video card get something PCI-e. Id recommend a 6800gs. Its good for games now, can be overclocked easily, and wont break your wallet.
get at least a 250gb hard drive. Space is cheap. look on Newegg.com for good prices, and not only on the hard drives.
Any dvd-rw drive would work fine in my opinion.
Sound card : audigy 2 gamer
Other than that, i suggest you check out the FS/FT forums to get the BEST POSSIBLE deal . If thats not your taste, by from newegg.com or zipzoomfly.com.
I suggest checking out silentpcreview.com, extremetech.com, hardforums ,overclockers.net. Look aroudn to see what you want to build then ask questions about specifics.